This section is intended to introduce various aspects of art that may be related to various aspects of the present techniques, which are described and/or claimed below. This discussion is believed to be helpful in providing background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art. The following descriptions and examples are not admitted to be prior art by virtue of their inclusion in this section.
The oil and gas industry is drilling upstream production wells of increasing depth and complexity to find and produce raw hydrocarbons. The industry routinely uses steel pipe, considered an Oil Country Tubular Good (OCTG) to protect the borehole (i.e., casing) and to control the fluids produced within the pipe (i.e., tubing). Such pipe, including casing and tubing, are made and transported in relatively short segments and installed in the borehole one segment at a time, with each segment being connected to the next. As the search for oil and gas has driven companies to drill deeper wells, pipes may be subject to increased complexity and magnitude of forces throughout their lifespans downhole. Industry demands have grown for casing, tubing, and connectors having increased tensile and pressure strengths. Furthermore, the developing area of deviated and horizontal wells have exacerbated this trend, further adding increased torsional loads as another requirement for casing and tubing connectors.
Connectors have been designed with varying thread, shoulder, and seal configurations. For example, two general connector thread configurations include a threaded and coupled connector and an integral connector. A thread and coupled connector includes a pin (i.e., a male threaded end) machined on relatively long joints of pipe and joined by the box (i.e., a female threaded end) machined on a relatively short coupling. An integral connector includes a pin threaded on a full-length pipe connected to a box threaded to another full-length pipe, and pin and box ends may be threaded onto opposite sides of each full-length pipe segment so that each segment may be connected for a length of a borehole. One type of shoulder and seal combination includes a center shoulder seal, which includes a sealing section in a connection disposed between at least two threaded portions. The sealing section of a pin or box may have direct contact with the sealing section of another pin or box and may function to prevent the passage of liquid or gas across the threads of the assembled connection. As industry demands connectors with increasingly high tensile strength, pressure strength, and torque, etc., the general features of connectors may be further designed and engineered to meet downhole performance criteria.